【摘要】 长英质片麻岩是太古宙变质杂岩区最主要的岩石类型。对其成因和机理的研究不仅对探索地壳早期演化有重要的理论意义,也直接关系到中深变质岩区地质调查工作的质量和找矿方向的确定。中高级变质岩区进行地质调查和研究工作要进行典型解剖。要特别注意不同成因长英质片麻岩之间和它们与其他围岩之间接触关系的研究。要加强对长英质片麻岩中原生结构、包体、副矿物(特别是锆石)和地球化学的研究。当长英质片麻岩的成因不能确定时,应以××片麻岩命名,可作为填图单位,但不要赋予成因含义。在中深变质的副片麻岩区填图时,应识别和划分出混合岩带。更多还原

【Abstract】 Felsic gneiss is the most widely distributed rock type in Archean metamorphic complex areas. The study of its origin and formation mechanism is not only of great significance in deciphering the early evolution of the crust, but also has a direct bearing on the quality of geological surveys of medium- and high-grade metamorphic areas and determination of the direction in mineral prospecting. The anatomy of typical areas is necessary for the geological survey and study in these areas. Special attention should be given to the study of the contact relationships between felsic gneisses of different origins and between them and other country rocks. It is very important to strengthen the study of the primary texture, enclaves, accessory minerals (especially zircon) and geochemistry. If the felsic gneiss is mappable on the geological map but its origin is ambiguous, it should be named ×× gneiss, without the genetic connotation in the rock names. The migmatite zone should be recognized and separated in mapping medium- and high-grade metamorphic paragneiss areas.更多还原